Submarine machines



July Z0, 1965 A, LACAM ETAL SUBMARINE MACHINES Filed April 2 1963 allUnited States Patent O 3,195,493 SUBMARNE MACHINES Andr Lac-am,Chaville, and Boris Vodar, Paris, France,

assignors to Centre National de la Recherche Scientiique, Paris, France,a French government administration Filed Apr. 2, 1963, Ser. No. 269,939Claims priority, application France, Apr. 4, 1962, 393,317 7 Claims.(Cl. 114-16) The present invention relates to submarine machines i.e. tomachines immersed in water.

We will rst remind some data relative to the problems of machinesintended to be used under water. Such machines generally consist of twoportions having distinct functions, to wit on the one hand the cabin forthe crew and the control means, the inside of this cabin being kept atatmospheric pressure whatever be the external hydrostatic pressure (thewalls of this cabin are therefore suiciently thick to be able to resistthe action of compression forces from the surrounding medium rso that,in most cases, the apparent density of this portion is much higher thanthat of water) and7 on the other hand, a float divided into compartmentsintended to work as water ballasts and to compensate for the excess ofweight of the lirst portion. This result is obtained by lling saidcompartments with a body or bodies of a density lower than that ofwater. Gases and liquids are mostly utilized to constitu-te said bodies.However, the use of such uids involves conditions correspondingessentially to their physical behaviour. As a matter of fact, these liftproducing iluids are, as a rule, generally more compressible than water.Consequently when the machine sinks deeper and deeper into water, thevolume of a given mass of such a fluid decreases more than that of thesame mass of water considered at the same depth. The result is anapparent increase of the weight of the machine due to a reduction of thearchimedean thrust. In known submarine machines intended to work atgreat depth, this phenomenon is compensated for in various manners. Inbathyscaphes, ballast 'is released as the depth increases. Without thisreduction of weight, the machine would move downwardly with a uniformlyaccelerated movement which would be braked only by friction forces. Inso. called Aquarius apparatus, which use a gas as sustaining duid, thegaseous volume is kept substantially constant by constantly addingfurther gaseous masses. Considering either of these apparatus inequilibrium in water, at a given depth, any displacement from theposition of equilibrium will tend to become greater and greater. Inother words the equilibrium is unstable.

The object of the present invention -is to obviate these drawbacks andto provide a machine of the above mentioned type which is kept in stableequilibrium without making use of any external force.

For this purpose, the upward force [is obtained at least partly by meansof bodies in the solid state, the specific mass and compressibility ofwhich are lower than the respective specific mass and compressibility ofthe surrounding liquid medium, i.e. water.

It can be shown that, in this case, the equilibrium of the machine isstable. This can be easily understood by supposing that thecompressibility of the sustaining bodies -is negligible. From the pointof view of the actions exerted thereon, the machine in equilibrium inthe liquid is then equivalent to an equal volume of the liquid presen-tinthe zone occupied by the machine and this zone is located between adenser zone located below it and a lighter zone located above it. If,for instance, the machine is moved upwardly into the upper zone, itsweight becomes ice higher than the thrust acting thereon and the resulttends to bring it back into its initial position. A similar reresultwould be produced if the machine were moved into the lower zone.

The machine according to this invention may have the followingcharacteristics, taken either separately or in different combinations:

(a) The sustaining bodies are non porous solids or solids provided withsmall holes therein, without communication between these holes, thesolubility of said solids in water being negligible;

(b) The sustaining bodies are solids coated with a suitable substancewhich may be varnish, paint, or a metal coating, or disposed in a sheathof thin plastic material, in order to prevent direct contact with thesurrounding liquid, i.e. water;

(c) The sustaining bodies are fluidtight hollow solids containing aiiuid, and more especially a gas, under pressure;

(d) The sustaining bodies are hollow solids having hooped walls.

The arrangements mentioned at (c) and (d) are intended to improve, byhooping or by production of an internal counter-pressure, the resistanceof the hollow bodies to the external hydrostatic pressure.

It is known that there are many substances that can be used for makingat an acceptable price sustaining bodies' corresponding to the abovecharacteristics.

By way of non limitative example we may cite long chain saturatedhydrocarbons and some of their acids, nitriles and ketones. One of themost known of these is stearic acid. However this substance i-s not themost favorable because it is very slightly soluble in water. Furthermoreits density is relatively high, being 0.847. On the contrary thecorresponding saturated hydrocarbon, octodecane, is not soluble in waterand its density is only 0.7768. Triphenylamine, of a density of 0.774,can also be used.

The use of hollow or alveolar bodies makes it possible to obtain, fromheavy materials such as metals, sustaining bodies of very low apparentdensity. Of course the mechanical properties of the material forming thewalls of said bodies must be suicient to enable the recesses both toresist the compression and to have walls thin enough to permit ofobtaining a low density. This last condition therefore implies a maximumrate of lling of the recesses. This rate may be determined in thefollowing manner; if d is the density of the surrounding liquid mediurn(water) and D that of the material of which the walls of the bodies aremade and if Vi 'and Ve are respectively the internal and the externalvolume of the body,

said body has a positive floatability if:

7 Vi a 1 JD The iioatability is the greater as the first member of theabove unequality exceeds the second member. Mechanical considerationssupply the lower limits below which the thickness or the walls must notdecrease. From this point of View itseems preferable, at the presenttime, to use a hollow sphere, which has a geometrical shape well adaptedto resist compression. The risks of breaking of the body appear when thetension supported by the wall is equal to or higher than the elasticlimit of the material. It is therefore necessary to use the materialbelow this limit. The,

tension t on the inner wall of a sphere subjected to an external uniformpressure P is given, according to Lam, by the following formula:

BRS

i wherein Rand rare the external and internal radii of the sphere,respectively; In the case of asphere made of steel,

the physical characteristics of which are as follows: density 7.7, yieldpoint 80 lig/mm?, it is possible to arrange so that the material'worksunder tensions lowerfthan orequal to 25 "kg/mm?, in ordertohaveafsuliicient safety margin.- f

In theser conditions, with'an" external pressure'averaging 100 kg./6111.2, the Lam formula indicates that the ratio of the radiimust beequal 'to 1.021. Y'I he. resulting density is.O.,462,` The sustainingpow'erof such spheres is there# fore much higher than that of solids.

It is possible to Y reach higher sustaining powers' by making use ofmaterials of lower densityv but having good mechanicalcharacteristics.'V For instance, with glass, in the same conditions .of

utilization, the density will be only 0.138.

^- Of course,'the spherical shape is not theonly oneV that can be usedaccording to our invention. Y n

According to the present invention itis possibleiurther FIG. r3V is anaxial section of a hollow body used according to thepresent'invention.f" Y The machine according to FIG. 1 comprises a cabin 1, with thickVwal-ls capable of resisting the external liquid pressure, supported bya oat 2 divided by walls 3 into compartments 4, 5, 6, 7,8, 9, 10,1^1,12. The division of this oatinto compartments facilitates thebalancing of the machine and improves safety` in case offshocks. Thecompartments in question each containa suitable amount ofsolidsustaining bodies 31. Each of the iioat compart. Y ments' 4, 5,16, y'7,9, 1), 11 and 12 contain solid sustaining bodie'sr31f' However thesebodies 31 do not iill up the above mentioned compartments bu'tzleavesome free space therein, which can be occupied'either by water enteringthrough ,holes 32 providediin'the lower walls thereof (the dimensions ofsaid holes 32 being of course smaller than those-of bodies 31 sothatsaidbodies'cannot escape from to increase thefresistance to externalpressure Vof the holv e low bodies that are used without considerablyincreasing their appar'ent'density by llin'g the recesses with'a fluidunder pressure Aand in particular with a gas'under pressure.

For instance thel internal pressure in the hollowfbody will n be'one'half of the hydrostatic pressure;

By proceeding in this manner, it is possible to reduce byY nearlyonehalt the valueof'the apparent density of the hollow body. Of coursethe fluid that is used 'must have a density as low as possible. vBy wayof non limitative ex-V ample we may operate as follows: A glasstube,.one of l the ends of which is initiallyV closed, is cooled inliquid nitrogen. YIt is subsequently partly filled with a certain y'and'13a connected through the ci'rcuitrshown by FIG. 2

= with the central chamber or compartment 8. This circuit comprises inparticular aV compressor 14 adapted to work in bothdirections, that isto lsay capabler of transferring Y gas from containers 13 intoYcompartment 8 and inversely frorncompartment 8 into containers 13 and13a. The gas y' circuit has been shown for compartment 8 buto courseamount of a liquefied gas and the tube is finally sealed.

The gas thus imprisoned in the glass tube creates, at nor- The thicknessmal temperature, the desired pressure. Y necessary for the walls of thetube can easily be calculated by means of the Lamformula. Concerning thesealing of the free end of the tube, it constitutes any operationwithout special diiiicultiesrfor someone skilled in the art.

It is interesting to note here the interest, from the point 1 1; .40

Y tion with cabin 1.

of view of safety, of using a highly divided-ballast such asobtainedib'y the use of hollow bodiesac'cording to the presentinvention. The risks of accident resultingl from shocks or mechanicalaccidents are greatly reduced.V

similar circuits may exist between containers 13 and 13 and compartmentsk4, 5, 6, 7, 9,111,11 and 12.

r For the sake of safety, the machine further `includes weights placedlin boxes 15 xed to cabin 1 and which can be dropped'separately.

r VHorizontal propulsion of the machine is obtained by meansdiagrarnmatically shown at 16.

I The central compartmentS, which is provided at the bottom thereof withcommunications with rcompartments Of course the presenty inventioncomprises the adapta-V'.Y

tion to existing machines of sustainingdevice vusing .as active elementssolid bodies such as above specified, which may replace more or less thesustaining means used prior to this invention. To be more deiinite, theinvention is concerned with 'a submarine machine wherein the iloat,V

v machine being possibly further characterizedby at least one of thefollowing points: Y Y

(a) The machine comprises a compressor plant making it possible to forcea gas under pressure into at least one f compartment so as to drive outwatertherefrom and whichY may work in the reversemanner when it isdesired to ex- 7'and 9 jin'addition to its use to control thel vert-icaldisplacement ofthe rmachine further serves as communica- For thispurposeit is tted :with closing means diagrammatically indicated at 17 and 18.

Finally cabin 1 is provided with windows 19 and l2i) for guiding themachine'and observing the surrounding medium.v We will now describe withVreference to FIG. 2 the gaseous 'circuit`forcontrolling the verticaldisplacements of they rmachine by transfer of gasV between .containers13 and 13 on the Yone hand and compartment 8 -on the Y Pressure gauges22 land 23 measure the pressures exist-r ing respectively in containers13 and'13a and in comparttract the gas from said compartment and` tolill said com-V v i.

partment with water;

l (b) The machine comprisesr a special compartment f giving it acomplete automaticity for its vertical displacements;

(c) The machine is provided with weights which can be dropped eitherseparately or at a single time;

(d) The machine is provided with a propelling device' for horizontaldisplacement; Y Y

(e) The machine is tted with auxiliary means forl per- Y forming variousworks during immersion. y

A preferred embodiment of our `invention'will be her yinafter describedwith reference to the appendedY drawings,v

given merely by way of example, and in which:

FIG. 1 diagrammatically shows, in verticalfsection, a"

machine of FIG. 1;

the

n ment 8. For instance, the'vertical displacement velocity may varyaccording to a given law, or the depth at which theimachine is under thesurface of water may be kept gas containers 13 and13a with adistributing machine 30 for sending gas to the other compartments. v

I iIG. 3 is a sectionalview of a hollow bodyi made of cylindricalportions 33 and 34.shrunk on each other and semi-spherical end portions35. f

In Va general mannerhwhile we have, in the above description, disclosedwhatwe deem to be a practical and eficientembod-iment Vof theinvention,it should be well v understoodV that We donot Wish tofbe limited theretoas V there `might be changes made in-the arrangement, dispositionandVform of the parts withoutdeparting from theiprinciple;- of the presentinvention as comprehended within the scope of the Vappended claims.

What we claim is:

1. A submarine machine comprising a frame and a Xed number of sustainingbodies at least the outer wall of which is solid and uninterruped, saidbodies being operatively connected with said frame to transmit theretoan upward thrust, the specific gravity of said bodies being less than 1and their compressibility being less than that of water, the number ofsaid bodies being such that the total upward thrust they exert in wateron said frame is equal to at least a substantial portion of the totalapparent weight in water of the remainder `of said machine.

2. A machine according to cla-im 1 wherein said bodies are made of a nonporous solid substance.

3. A machine according to claim 1 wherein said bodies are made of asolid substance having a multiplicity of non communicating cavitiestherein.

4. A machine according to claim 1 wherein said bodies consist of a solidsubstance and a watertight coating surrounding said substance.

5. A machine according to cla-im 1 wherein said bodies are hollow solidbodies.

6. A machine according to claim 1 wherein said bodies are hollow solidbodies filled with a gas under pressure.

7. A submarine machine which comprises, a frame, a float rigid with saidframe comprising a plurality of compartments, at least some of saidcompartments being provided, at the bottom thereof, with openingsplacing the inside thereof in communication with the outside, a cabin, axed number of sustaining bodies in said last mentioned floatcompartments, at least the outer walls of each of bodies being solid anduninterrupted, the specific gravity of said bodies being less than 1 andtheir compressibility being less than that of water, the number of saidbodies being such that the total upward thrust they exert in water onsaid oat is equal t-o a substantial portion of the total apparent weightin water of the remainder of said machine, and means carried by saidframe for driving a gas into at least some of said compartments to expelwater therefrom.

References Cited by the Examiner UNITED STATES PATENTS 2,857,873 10/ 58Norelli 114-50 3,104,641 9/63 Froehlich 114-16 FOREIGN PATENTS 622,900 549 Great Britain. 1,261,635 4/61 France.

PERGUS S. MIDDLETON, Primary Examiner.

MILTON BUCHLER, Examiner.

1. A SUBMARINE MACHINE COMPRISING A FRAME AND A FIXED NUMBER OFSUSTAINING BODIES AT LEAST THE OUTER WALL OF WHICH IS SOLID ANDUNINTERRUPED, SAID BODIES BEING OPERATIVELY CONNECTED WITH SAID FRAME TOTRANSMIT THERETO AN UPWARD THRUST, THE SPECIFIC GRAVITY OF SAID BODIESBEING LESS THAN 1 AND THEIR COMPRESSIBILITY BEING SUCH THAT THAT OFWATER, THE NUMBER OF SAID BODIES BEING SUCH THAT THE TOTAL UPWARD THRUSTTHEY EXERT IN WATER ON SAID FRAME IS EQUAL TO AT LEAST A SUBSTANTIALPORTION OF THE TOTAL APPARENT WEIGHT IN WATER OF THE REMAINDER OF SAIDMACHINE.